Learning Resource Type

Classroom Resource

What Are Perfect Squares?: Algebra 1, Episode 19: Unit 7, Lesson 11 | Illustrative Math

Subject Area

Mathematics

Grade(s)

9, 10, 11, 12

Overview

This video lesson has two key aims. The first aim is to familiarize students with the structure of perfect-square expressions. Students analyze various examples of perfect squares. They apply the distributive property repeatedly to expand perfect-square expressions given in the factored form (MP8). The repeated reasoning allows them to generalize expressions of the form (x + n)2 as equivalent to x2 + 2nx + n2.

The second aim is to help students see that perfect squares can be handy for solving equations because we can find their square roots. Recognizing the structure of a perfect square equips students to look for features that are necessary to complete a square (MP7), which they will do in a future video lesson.

    Mathematics (2019) Grade(s): 09-12 - Algebra I with Probability

    MA19.A1.5

    Use the structure of an expression to identify ways to rewrite it.

    Unpacked Content

    UP:MA19.A1.5

    Vocabulary

    • Terms
    • Linear expressions
    • Equivalent expressions
    • Difference of two squares
    • Factor
    • Difference of squares

    Knowledge

    Students know:
    • Algebraic properties.
    • When one form of an algebraic expression is more useful than an equivalent form of that same expression.

    Skills

    Students are able to:
    • Use algebraic properties to produce equivalent forms of the same expression by recognizing underlying mathematical structures.

    Understanding

    Students understand that:
    • Generating equivalent algebraic expressions facilitates the investigation of more complex algebraic expressions.
    Mathematics (2019) Grade(s): 09-12 - Algebra I with Probability

    MA19.A1.6

    Choose and produce an equivalent form of an expression to reveal and explain properties of the quantity represented by the expression.

    Unpacked Content

    UP:MA19.A1.6

    Vocabulary

    • Quadratic expression
    • Zeros
    • Complete the square
    • Roots
    • Zeros
    • Solutions
    • x-intercepts
    • Maximum value
    • Minimum value
    • Factor
    • Roots
    • Exponents
    • Equivalent form
    • Vertex form of a quadratic expression

    Knowledge

    Students know:
    • Techniques for generating equivalent forms of an algebraic expression, including factoring and completing the square for quadratic expressions and using properties of exponents.
    • When one form of an algebraic expression is more useful than an equivalent form of that same expression to solve a given problem.

    Skills

    Students are able to:
    • Use algebraic properties including properties of exponents to produce equivalent forms of the same expression by recognizing underlying mathematical structures.
    • Factor quadratic expressions.
    • Complete the square in quadratic expressions.
    • Use the vertex form of a quadratic expression to identify the maximum or minimum and the axis of symmetry.

    Understanding

    Students understand that:
    • Making connections among equivalent expressions reveals the roles of important mathematical features of a problem.
    Mathematics (2019) Grade(s): 09-12 - Algebra I with Probability

    MA19.A1.9

    Select an appropriate method to solve a quadratic equation in one variable.

    Unpacked Content

    UP:MA19.A1.9

    Vocabulary

    • Completing the square
    • Quadratic equations
    • Quadratic formula
    • Inspection
    • Imaginary numbers
    • Binomials
    • Trinomials

    Knowledge

    Students know:
    • Any real number has two square roots, that is, if a is the square root of a real number then so is -a.
    • The method for completing the square.
    • Notational methods for expressing complex numbers.
    • A quadratic equation in standard form (ax2+bx+c=0) has real roots when b2-4ac is greater than or equal to zero and complex roots when b2-4ac is less than zero.

    Skills

    Students are able to:
    • Accurately use properties of equality and other algebraic manipulations including taking square roots of both sides of an equation.
    • Accurately complete the square on a quadratic polynomial as a strategy for finding solutions to quadratic equations.
    • Factor quadratic polynomials as a strategy for finding solutions to quadratic equations.
    • Rewrite solutions to quadratic equations in useful forms including a ± bi and simplified radical expressions.
    • Make strategic choices about which procedures (inspection, completing the square, factoring, and quadratic formula) to use to reach a solution to a quadratic equation.

    Understanding

    Students understand that:
    • Solutions to a quadratic equation must make the original equation true and this should be verified.
    • When the quadratic equation is derived from a contextual situation, proposed solutions to the quadratic equation should be verified within the context given, as well as mathematically.
    • Different procedures for solving quadratic equations are necessary under different conditions.
    • If ab=0, then at least one of a or b must be zero (a=0 or b=0) and this is then used to produce the two solutions to the quadratic equation.
    • Whether the roots of a quadratic equation are real or complex is determined by the coefficients of the quadratic equation in standard form (ax2+bx+c=0).
    Mathematics (2019) Grade(s): 09-12 - Algebra II with Statistics

    MA19.A2.11

    Solve quadratic equations with real coefficients that have complex solutions.

    Unpacked Content

    UP:MA19.A2.11

    Vocabulary

    • Complex solution
    • Quadratic equation
    • Real coefficients

    Knowledge

    Students know:
    • strategies for solving quadratic equations

    Skills

    Students are able to:
    • apply the quadratic equation.
    • provide solutions in complex form.

    Understanding

    Students understand that:
    • all quadratic equations have two solutions: real or imaginary.
    • Some contextual situations are better suited to quadratic solutions.
    Link to Resource

    CR Resource Type

    Audio/Video

    Resource Provider

    PBS
    Accessibility

    Accessibility

    Video resources: includes closed captioning or subtitles
    License

    License Type

    CUSTOM
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